Main Navigation

Q&A /

Fixing 3 Way Switch & 4 Way Switch Wiring Problems

What is this special black screw on a 3 way switch? Copyright 2017 Tim Carter

Fixing a 3 Way Switch TIPS

Use a voltage tester to help with this job

You just need to identify the continuous hot wire and the wire that goes to the light fixture

WATCH the EASY VIDEOS below

Be careful working with energized conductors

CLICK HERE to Get Tim's FREE & FUNNY Newsletter!

Existing 3 Way Switches

Virtually every house has at least one set of three way switches. They may be at the bottom and the top of stairways. Often they can be found at either end of a hallway. If one breaks or you wish to replace them with more decorative switches, you can often confuse the wires.

How to Wire a 3 Way Switch Video

If you hook up either one or both of the three way switches incorrectly, they will not operate properly. One switch may turn the lights on and off, while the other switch does nothing.

Which Wire is What?

Let's assume you are in a mess right now. The switches don't work. You don't have a continuity tester. Here is how to fix them. The first thing that must be done is to identify the two common or traveler wires. WATCH THE ABOVE VIDEO to see what those wires are.

Identifying the travelers at each switch is done by finding the continuous hot wire at one switch and then discovering the wire at the other switch that goes to the light fixture.

One of the wires in the two three-way switches is ALWAYS hot assuming the circuit breaker is on.

Start by turning off the power to the switch circuit at the circuit breaker.

Disconnect all the wires from BOTH switches.

Be sure the wires are NOT touching anything and the bare copper ends are sticking out of the boxes and not touching anything.

Using a Voltage Tester

Use a voltage tester to find it. Watch this video to see how to use a voltage tester while a wire is HOT:

Be Careful

To identify the hot wire with a voltage tester, you need to work with the electric while it's energized.

Once you identify the HOT wire, connect that wire to the black screw at the switch you're working on. Refer once again to my own video above. Watch it again.

Go to the other switch and now find the wire that goes to the light fixture. You can do this using an extension cord that's plugged into an outlet. When you insert each of the wires at the second switch ONE AT A TIME into the hot plug socket on the extension cord, the light above will come on.

Take this wire and attach it to the black screw on the switch.

Attach the remaining two wires at each switch to the brass screws. It doesn't matter which wire goes to with brass screw.

SPONSORS /

18 Responses to Fixing 3 Way Switch & 4 Way Switch Wiring Problems

I understand how to wire a 4 way switch between two 3 way switches to give me 3 switch positions to turn on/off a light. BUT how do I wire it so I can turn on/off a light from FOUR different positions? Do I just install another 4 way switch between to two 3 way switches? Please answer as soon as possible! THANK YOU!

I am trying to follow your drections in the following "Fixing 3 Way Switch & 4 Way Switch Wiring Problems". It appears that some of the instructions are incomplete. I believe there should be more detail after "Now it's time to be CAREFUL." Can you provide me with a complete set of instructions as soon as possible.

I agree with the Al DePresco. It's impossible to find where on your posting the relevant video link is. You're likely not aware of how your page shows on some computers, like mine. I clicked on something that I thought was the video and antivirus software started to be downloaded on my computer without my permission. Someone, like one of your sponsors, has taken control of your website and made it useless, at least on my browser (Firefox)

Jeff, Do you have a super narrow monitor? That could be the issue. The site renders fantastic on every browser I test it on including Firefox. CLICK HERE for the 3 Way Switch video. CLICK HERE for the 4-Way Switch video.

Tim, I agree with Jeff and Al. I can find the videos just fine. But they are about how to INSTALL 3 or 4 way switches, while the text is about how to diagnose faulty circuits already installed. The text gives the set up on how to do the diagnostics, but then stops short. No link to next page, no additional column on a wider monitor, etc... Just the warning that now you have to be careful for the next step.... NO NEXT STEP.

I am working on a circuit with two each 3 ways (on the "ends" of the circuit) and three each 4 ways in the middle. Need to know how to figure out which wires are not installed correctly (all new switches).

I installed three hallway light fixtures in place of one all were working now a week later none do could my three way switches at each end of hallway have gone out I rechecked all wiring from box in ceiling to each light and there are no circuits blown do three way switches go out will none work then

Rarely do the switches go bad. Check to see if you have power coming into one of the 3-way switches. If not, that means a breaker is blown or a wire is loose downstream between the switches and the electric panel.

I have a circuit of 2 three way switches and 1 four way switch. When the four way switch is in the power on position, I can turn the lights on and off with the three way switches. When the four way switch is in the off position, none of the switches work. Any suggestions? Thanks.

Is there such a thing as having two 3 way switches operating a light in a way that up is always on regardless of the position of the other switch? In other words, I can't stand having to flip a switch down to turn the light on.

Nope. What you desire is impossible. It all depends on the orientation of the switch the LAST TIME you flipped it to make the light go on and off. Then add in the random factor of entering the hallway or staircase from a different direction and operating the switch.

If you flip a switch up side down and try to do what you want, sooner or later you'll be at one switch and you want the light to go ON, but the switch is pointing up. Go ahead and try it. You'll see what I mean.

Hi tim, I have a hall light that can be turned on 3 different places. I see you need 2 3 ways switches and one 4 way switch that goes in the middle of the 2 3ways. Well heres the dea. There has been a plate over a wall switch. I thought t looked like it went to the entry way light that lread had 2 switches to turn it on and off. So I hooked up a switch and it turned it one and I turned it off and on again it tripped the breaker. I then watched your video about the 2 3 ways and the 4 way in the middle. The problem is that the box that was covered only has a white, black, and ground wire so what do I do?

I have a 4 way circuit and it has worked for 10 years. Recently it tripped the breaker. I isolated it the 4 way switch. The 4 way is wired with the power to the 3 way switch first, then the 4 way, 3 way and then lights. The last 3 way turns the lights on and off, but when I use the first 3 way and 4 way, it trips the breaker?? I replaced the 4 way switch and it remains unsolved for now.

to id the wires o a 3 way switch, all you need are some wire nuts. turn power OFF, label the switches A & B. disconnect switch, and connect all 3 wires together with a wire nut. switch B, disconnect all the wires and connect TWO wires together. turn the power ON. If the light stays off , label the 3ed wire black, if not, connect next two together. until you find a pair that the light stay off. Label 3ed wire black. now connect all 3 wires together. now do the same for switch A. Then connect the wirer labeled black to the dark screw, The other 2 wires to the silver screws. Connect the wires the same way on the other switch, TURN POWER ON
LET THER BE LIGHT